Photovoltaics
Using the sun
to generate
electricity
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Solar Wonders, ©2007 Florida Solar Energy Center
An increasingly popular use of solar energy
involves solar electric systems, called
photovoltaics.
Photovoltaic (PV) systems convert
sunlight directly into electricity, and
are potentially one of the most
useful of the renewable energy
technologies.
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Solar Wonders, ©2007 Florida Solar Energy Center
On a planet where more than two billion people have
no access to electricity, PV systems can provide
power for many uses.
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Solar Wonders, ©2007 Florida Solar Energy Center
The heart of a photovoltaic system is a solid-state
device called a solar cell.
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Solar Wonders, ©2007 Florida Solar Energy Center
Groups of solar cells can be packaged into
modules, panels and arrays to provide useful
output voltages and currents to provide a
specific power output.
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Solar Wonders, ©2007 Florida Solar Energy Center
Photovoltaic power is ideal for remote applications
where other power sources are impractical or
unavailable, such as in the Swiss Alps.
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Solar Wonders, ©2007 Florida Solar Energy Center
This mountain hut in a very remote area
of France uses PV to generate power.
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Solar Wonders, ©2007 Florida Solar Energy Center
Here is a lighthouse along the coast of Eritrea in
Africa. Before this PV system was installed, the
Lighthouse relied on bottled gas for power – a system
that required constant maintenance and a permanent
staff on site.
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Solar Wonders, ©2007 Florida Solar Energy Center
Here is a stand-alone PV system in Oix, La Garrotxa in rural
Spain. This system consists of a 900-watt PV array with
inverter and batteries. More than 60 rural homes in this
mountainous area have been electrified with PV.
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Solar Wonders, ©2007 Florida Solar Energy Center
PV power for off-shore navigational aids
eliminates trips to and from shore to refill
generators with fossil fuels.
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Solar Wonders, ©2007 Florida Solar Energy Center
Solar-powered water pumps are very efficient and
cost-effective in agricultural applications like this
system in Kansas.
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Solar Wonders, ©2007 Florida Solar Energy Center
Another farm application – keeping animals where
they belong, behind PV-electrified fence chargers.
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Solar Wonders, ©2007 Florida Solar Energy Center
PV-powered
streetlights like these
in a rural town in
Central America help
contribute to the
safety, security and
general standard of
living in remote areas
all over the world.
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Solar Wonders, ©2007 Florida Solar Energy Center
The lamp in this PVpowered insecttrap comes on
automatically after
sunset. It
attracts insects
which collide with
the metal grid and
drop into the
receiver below.
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Solar Wonders, ©2007 Florida Solar Energy Center
PV applications
include lighting for
remote signs like
this outdoor board
along a U.S.
highway.
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Solar Wonders, ©2007 Florida Solar Energy Center
Off-shore navigational
aids, which require
little maintenance, can
withstand harsh
storms, and cut down
on the cost and
pollution of battery
replacement and
disposal by using PV
for power.
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Solar Wonders, ©2007 Florida Solar Energy Center
Highway directional signs can use PV systems to
save the expense of excavation to extend electric
lights to the sign as well as the cost of maintaining
the electric line.
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Solar Wonders, ©2007 Florida Solar Energy Center
PV is an excellent
source of power for
battery chargers for
boats, vehicles, and
equipment. The solarpowered charger
assures that the
battery is charged
and ready for use,
even if the boat or
vehicle has sat for a
long time and the
battery has
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discharged.
Solar Wonders, ©2007 Florida Solar Energy Center
Campers can use PV in remote areas to
provide power for lighting, appliances
and other uses.
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Solar Wonders, ©2007 Florida Solar Energy Center
It is estimated that more than 15,000 homes in remote parts
of the U.S. rely on PV systems to meet their energy needs.
In many cases, it is more cost-effective to install a PV
system than pay the costs of having the utility company
extend the power lines to the home.
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Solar Wonders, ©2007 Florida Solar Energy Center
Many utility companies in the U.S. are turning to
large PV systems to help meet peak power demand
and reduce the need for building new power plants.
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Solar Wonders, ©2007 Florida Solar Energy Center
Around the world, there are many dramatic examples of PV
systems. They include this PV-wind-diesel hybrid system in
Mexico that provides village-wide power for 43 homes, three
schools, two stores, a church and an auditorium.
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Solar Wonders, ©2007 Florida Solar Energy Center
In 1987, the Swiss government started a
program to mount PV arrays on a sound
barrier along a main motorway.
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Solar Wonders, ©2007 Florida Solar Energy Center
This billboard in Mexico promotes a project
that uses solar power to electrify
streetlights.
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Solar Wonders, ©2007 Florida Solar Energy Center
This photovoltaic system in the Philippines not only
provides electricity to the home, but also creates a
shelter for this motorcycle.
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Solar Wonders, ©2007 Florida Solar Energy Center
PV modules are used in this remote area in Africa north of
Nairobi at the Kenya Gliding Club to charge batteries in VHF
radios in gliders, to maintain the starter battery in the tow
vehicle which moves the gliders around the airstrip, and to
power other instruments.
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Solar Wonders, ©2007 Florida Solar Energy Center
Maybe no uses are
as dramatic and
important as the
portable PV panels
and small
refrigerators
carried around
Africa on the
backs of camels.
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Solar Wonders, ©2007 Florida Solar Energy Center
Refrigerators like
this, carried on the
backs of camels and
powered by PV panels,
allow vaccines to be
kept in good condition
and transported to
remote villages where
medicines are needed.
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Solar Wonders, ©2007 Florida Solar Energy Center
This is the
entrance sign at a
Wisconsin state
park. The PV
system powers
lights that operate
from dusk to dawn.
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Solar Wonders, ©2007 Florida Solar Energy Center
This restroom PV
lighting system at
a state park has
exterior amber
LED lights, interior
white LED lights,
and a fluorescent
light in a
storeroom.
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Solar Wonders, ©2007 Florida Solar Energy Center
A PV-powered
police car in
Zermatt,
Switzerland. Only
electric, solarpowered, or horsedrawn vehicles are
allowed in this
quaint town in the
Alps.
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Solar Wonders, ©2007 Florida Solar Energy Center
A photovoltaic kit
is used to recharge
portable lamps in
the Ivory Coast in
Africa.
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Solar Wonders, ©2007 Florida Solar Energy Center
This solar panel powers a light in a bus
shelter in Australia, providing security and
convenience at night.
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Solar Wonders, ©2007 Florida Solar Energy Center
In many parts of the world, getting water is as
important as getting energy. This experimental
system in Israel uses PV and wind energy in a
desalination project.
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Solar Wonders, ©2007 Florida Solar Energy Center
Discussion Questions
• Are PV systems as efficient or
economic as fossil-fueled systems?
• Is PV a viable alternative for all of
our power needs? For homes? For
vehicles? For other needs?
• Is PV the answer to all of the world’s
power needs?
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Solar Wonders, ©2007 Florida Solar Energy Center